Socket for starting switches



g- 1942- N. CHIRELSTEIN 2,292,052

SOCKET FOR STARTING SWITCHES Filed NOV. 6, 1941 Nathan aul'relslem,

I N V EN TOR.

Patented Aug. 4, 1942 UNITED STATES PATENT OFFICE SOCKET FOR STARTING SWITCHES Nathan Chirelstein, Maplewood, N. J.

Application November 6, 1941, Serial No. 417,980

1 Claim.

The invention here disclosed relates to socket constructions for the switches used in starting fluorescent lamps and the like.

Objects of the invention are to provide a simple, inexpensive form of socket, which while permitting easy insertion and ready removal of the starter switch, will securely hold the switch in place against vibration or anything other than intentional removal and while so holding, will maintain good mechanical and electrical engagement between the contacts of the socket and the contacts of the inserted switch.

Other desirable objects and the novel features by which the purposes of the invention are attained will appear in the course of the following specification.

The drawing accompanying and forming part of the specification illustrates several different embodiments of the invention and it is to be understood that the structure may be further modified and changed as regards the immediate disclosure, all within the true intent and broad scope of the invention as hereinafter defined and claimed.

Fig. 1 is a plan view of one commercial embodiment of the invention, with parts which ordinarily are hidden indicated in broken lines.

Fig. 2 is a longitudinal sectional view of the socket as on substantially the line 2-2 of Fig. 1 and with a switch unit indicated in place therein ing modified forms of the socket contacts and with the cooperating switch contacts indicated in broken lines in each View.

In Figs. 1 and 2, the socket is shown as comprising an insulating base H], recessed at H, to rotatably receive the starter switch I2.

At the back or bottom of the recess is a partition l3, having oppositely disposed arcuate slots l4, 15, for the contact terminals 16, ll, on the end of the switch unit.

The opposed arcuate contact receiving slots l4, l5, are of keyhole design and arranged with the larger ends of the same diagonally opposite to freely pass the terminal studs l6, l1, and narrower from there on to admit only the reduced or stem portions IQ of the studs, this construction cooperatively enabling the entry of the studs by a straight line movement and then the interlock ing of the studs with the partition wall by a partial rotary movement of the switch unit.

At the back of the slotted partition wall, the socket contacts 20, 2|, are disposed, these being Figs. 3, 4, 5, 6 are broken plan views illustrat extending lengthwise in respect to and in back of the slots [4, l5.

In the first form of the invention illustrated Figs. 1 and 2, these flat socket contacts are formed each with a transverse raised embossment 22, located substantially in line with the narrower portions of the slot. These embossments extend less than the full width of the contact strips, so as to leave the edges practically undisturbed and the strips therefore are of the same original length and not weakened to any appreciable extent by any lengthening or attenuating action, because of such embossment.

So located, these transverse ridges are out of the way of the terminal studs inserted in the larger ends of the slots and hence do not interfere in any way with the free insertion of the switch in the socket. Upon commencement of the rotary movement of the switch and preferably just following the start of engagement of the reduced portions of the contact studs in the narrow portions of the slots, the ends of the studs will engage the outer inclined sides 23, of the ridges, thus to wedge or cam the contact strips back and enable the ends of the studs to slide freely over the top of the ridges and the inner inclined sides 24, of the ridges to drop in behind the studs, as in Figs. 1 and 2.

In the latter relation, the contact studs are yieldingly retained in position at the inner smaller ends of the slots and a positive application of force will be then required to rotate the switch unit in the opposite direction to force back the contact springs and release the unit from the socket.

At the start of the releasing movement, the inclined inner faces 24, of the retaining abutments 22, serve as cams under engagement by the terminal studs in the same manner as the outer inclined sides 23, act as cams in the engagement of the unit in the socket.

To hold the switch the more securely in the socket, the contact springs are preferably arranged as shown in Fig. 1, with the free ends of the same back of the larger ends of the arcuate slots and the smaller portions of the slots extending inward or toward the firmer and less flexible supported ends of the contact blades.

With this arrangement and combination, the terminal studs of the switch engage the free and more resilient end portions of the contacts and in the rotary travel, move inward over the stiirer and less yielding portions of the contacts. Hence the engagement between the switch tershown as substantially fiat straight spring strips minals and socket contacts becomes firmer and more positive as the switch reaches its finally seated relation. Also this novel arrangement may require the use of a greatr force to turn the switch in a releasing direction than was required for inserting the switch in the socket. This makes it the more certain that the switch will not accidentally become loosened in the socket.

The contact springs are shown as substantially all in the same fiat plane and with the retaining embossments struck up from the flat plane, this leaving contact'areas in back of or behind the embossments at least as high as the free ends of the blades, Fig. 2, assuring full firm spring engagement of the blades with the ends of the contact studs in the fully seated relation of the latter. This holding tension is enhanced in the combination disclosed, where the switch studs rotate inward from the freeends of the fiat contacts to reach the locked position in the socket.

In Fig. 2, the base is shown as chambered at the back of the slotted partition at 25, to provide ample space for necessary movement of the spring contacts, this chamber being closed over by a protective back plate -26.

Fig. 3 illustrates a modified form of retainer construction embodying in place of the short transverse ridge, a series of embossments 21, in a transverse row between and terminating short of the longitudinal edges of the contact strip.

In Fig, 4, the retainer consists of a circular inclined sided flat top protuberanc 28, indented or struck upward from the fiat plane of the strip and likewise located entirely between the uninterrupted straight edges of the strip.

Fig. 5 illustrates a variation of the latter form of retainer, the same being a circular inclinedsided ring 29, pressed up from the body of the blade between the side edges. This ring may be of a size to receive the end of the contact stud in the final position of the latter at the narrow end of the slot in the base.

Fig. 6 illustrates a further modification, comprising arcuate ridges 30, struck up from the flat plane of the strip between the edges thereof and disposed to form convergent ways for directing the stud thereover in either direction.

In all forms of the invention, the switch is yieldingly held in interlocked relation in the socket against vibration or other disturbing forces and can only be released by a purposeful application of force to that end. In the interlocked condition, the switch terminals are retained at the best position for full firm engagement with the socket contacts. The improvements can be incorporated at slight or practicallyno additional cost and with no extra expense as 'to assembling or other necessary operations.

What is claimed is:

A socket for starting switches, comprising a socket base of insulating material recessed to rotatably receive a starter switch and having a wall at the bottom of the recessed portion with oppositely disposed arcuate slots therein formed with diagonally opposite enlarged ends to admit the headed contact studs on the end of a starting switch'entered in the recess, .flat spring contact strips mounted in spaced relation at the back of said arcuate slots andshort transversely extending raised ridges across the middle portions of said contact strips and wholly removed inwardly from both side edges of said strips, said intermediately disposed raised ridges being in the form of 10W em-bossments located substantially at the junctions of the narrower with the larger end portions of the slots and having inclined shoulders at opposite sides faced toward the narrower and toward the larger portions of said slots to serve as cams under engagement of the'headed studs to force back the contact :strips in rotary movement in either direction of a starting switch inserted in the recess of the base.

NATHAN CHIRELSTEIN. 

